1. Field of the Invention
This invention relates in general to power supply circuits, and, more particularly, to high-efficiency inverter circuits operable to provide high voltage outputs.
2. Description of the Prior Art
As is well-known in the art, the main function of an inverter circuit is to convert a direct or DC input voltage into an alternating or AC voltage output. See, for example my U.S. Pat. No. 4,184,128, issued Jan. 15, 1980, and entitled "High Efficiency Push-Pull Inverters"; Murray et al. U.S. Pat. No. 3,467,852, issued Sept. 16, 1969, entitled "High Speed Controlled Switching Circuit"; Engel et al. U.S. Pat. No. 3,753,071, issued Aug. 14, 1973, for "Low Cost Transistorized Inverter"; and Suzuki et al. U.S. Pat. No. 4,031,454, issued June 21, 1977, entitled "Transistor Inverter".
In certain applications of inverter circuits, such as energizing fluorescent or other gas discharge lamps, it is important to provide high voltages both for starting ease and efficient operation. The following U.S. patents are believed to be representative of the prior art relevant to such lamps and energizing circuits therefor:
__________________________________________________________________________ Patentee Patent No. Issue Date Title __________________________________________________________________________ Morley 2,279,635 Apr. 14, 1942 LUMINOUS VAPOR LAMP Miller 2,298,961 Oct. 13, 1942 FLUORESCENT LAMP Polevitzky 2,405,518 Aug. 6, 1946 ILLUMINATING DEVICE Rogers 2,505,993 May 2, 1950 FLUORESCENT ELECTRIC LAMP Dupuy 2,525,022 Oct. 10, 1950 CIRCULAR LIGHTING FIXTURE Baumgartner et al. 2,817,004 Dec. 17, 1957 ADAPTER HOLDER FOR CIRCULAR LAMPS Fry 2,878,372 Mar. 17, 1959 CIRCULAR LIGHTING FIXTURE Reaves 3,059,137 Oct. 16, 1962 SCREW-IN FLUORESCENT LIGHTING FIXTURE Grunwaldt 3,084,283 Apr. 2, 1963 TRANSISTOR-BATTERY SUPPLY FOR GAS DISCHARGE TUBES Wenrich et al. 3,155,875 Nov. 3, 1964 HIGH FREQUENCY BALLAST FOR FLUORESCENT LAMPS Genuit 3,263,122 July 26, 1966 CURRENT LIMITING INVERTER CIRCUITS AND APPARATUS FOR OPERATING ELECTRIC DISCHARGE LAMPS AND OTHER LOADS Johnson 3,634,681 Jan. 11, 1972 INTEGRAL BALLAST, LAMP- HOLDER SUPPORT AND WIREWAY Piccola 3,704,212 Nov. 28, 1972 ADJUSTABLE LIGHT FIXTURE FOR U-SHAPED LAMPS Anderson 4,093,893 June 6, 1978 SHORT ARC FLUORESCENT LAMP Wheeler 4,093,974 June 6, 1978 FLUORESCENT LIGHT FIXTURE Miller 4,161,020 July 10, 1979 FLUORESCENT LAMPHOLDER ASSEMBLY FOR CIRCLINE LAMP Young et al. 4,173,730 Nov. 6, 1979 COMPACT FLUORESCENT LAMP UNIT HAVING INTEGRAL CIRCUIT MEANS FOR DC OPERATION __________________________________________________________________________
While gas discharge lamp units and associated energizing circuits are generally known in the prior art typified by these patents, need has arisen for improved devices of these types, particularly inexpensive, reliable and highly efficient inverter circuits which can be employed to provide high voltage outputs suitable for energizing gas discharge lamps.